1. Field of the Invention
The present invention relates to a bumper back beam for a vehicle, and more particularly, to a bumper back beam for a vehicle including of a side portion, both sides of which are connected to a vehicle body and an intermediate portion for connecting the side portion on both sides, which are formed of different materials.
2. Description of Related Art
Generally, a bumper back beam is installed on the front part and the rear part of a vehicle so as to protect a vehicle body, and further a passenger, with respect to a collision.
According to a related art, a back beam that is made of steel has been used to ensure sufficient rigidity thereof; however, it is a recent trend to mainly use a back beam that is made of a composite material of plastic and steel, or plastic of different materials having different strength. This trend is due to the problems of increasing weight and deterioration of fuel efficiency.
Here, as shown in FIG. 1, the back beam formed of different plastic materials is comprised of a side portion 1, both sides of which are connected to a vehicle body and an intermediate portion 2 for connecting the side portion 1 on both sides are made of high strength plastic and general-strength plastic, respectively.
The side portion 1 is a crash box to be connected to a side member consisting of a vehicle body, through which impact energy is transferred toward a vehicle body while its outer form is collapsed by a load produced when the vehicle collides, and the intermediate portion 2 corresponds to a rail portion, through which the impact energy is absorbed through self-deformation when a vehicle collides.
The intermediate portion 2 may preferably be formed of high-strength plastic so as to ensure sufficient rigidity and the side portion 1 may preferably be made of general-strength plastic so as to easily transfer impact energy toward a vehicle body.
The back beam formed of different materials such as high-strength plastic and general plastic as described above may be configured to sufficiently ensure the rigidity, thereby safely protecting a vehicle body and a passenger when a vehicle collides.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.